12.1 Configuring Channel Defaults

Many configurations involve repetition of various channel keywords on
all or nearly all channels. Maintaining such a configuration is both tedious
and error-prone. To simplify some configurations, you can specify which keywords
are defaults for various channels.

For example, the following line in a configuration file indicates that
all channel blocks following the line will inherit the keywords specified
in the line:

defaults keyword1keyword2keyword3 ...

The defaults line can be thought of as a special
channel block that changes the keyword defaults without actually specifying
a channel. The defaults line also does not require any
additional lines of channel block information (if any are specified they will
be ignored).

There is no limit on the number of defaults lines
that can be specified—the effects of multiple defaults lines are cumulative
with the most recently encountered (reading from top to bottom) line having
precedence.

It may be useful to unconditionally eliminate the effects of any defaults lines starting at some point in the configuration file (at the
start of a standalone section of channel blocks in an external file, for example).
The nodefaults line is provided for this purpose. For example, inserting the
following line in the configuration file nullifies all settings established
by any previous defaults channel and returns the configuration to the state
that would apply if no defaults had been specified:

nodefaults

Like regular channel blocks, a blank line must separate each defaults or nodefaults channel block from other channel
blocks. The defaults and nodefaults channel
blocks are the only channel blocks which may appear before the local channel
in the configuration file. However, like any other channel block, they must
appear after the last rewrite rule.